1. Field of the Invention
The invention relates to a sleeve, particularly a rod sleeve, consisting at least of:                a core made of metal or plastic (e.g. on the basis of polyphenylene ether), comprising a core hub that has two faces with a first and a second diameter, and a core pin which extends in the direction of the longitudinal axis, which projects over both faces of the core hub while forming two connecting journals;        an outer sleeve that also consists of metal or plastic; as well as        an elastic layer that is arranged between the core hub and the outer sleeve.        
2. Prior Art
Sleeves of this type, whereby reference is particularly made to the references DE 30 04 194 A1, DE 42 08 448 C2, and DE 199 13 777 C1, are predominantly used in rail vehicle technology, which will be explained in greater detail in the following.
A significant aspect is the guidance of the wheel set of a rail vehicle by means of an elastic, play-free joint, linearly in the three directions of space, and torsionally, i.e. cardanically around the point of rotation of a guide arm, which is attached to the frame of the rail vehicle by means of a guide element (rod sleeve). In this connection, the longitudinal axis and height axis of the vehicle lie in the radial direction of the guide element, while the crosswise axis of the vehicle lies in the axial direction of the guide element.
With the background of this technology, the following requirements must be met:
a) One significant requirement is great rigidity in the radial and the axial direction. The required ratio of radial to axial rigidity is approximately 1:1 to 3:1. At the same time, a low torsion rigidity with simultaneous great cardanic rigidity is desirable. The ratio of cardanic rigidity to torsion rigidity should usually be approximately 10:1.
In the case of a conventional cylindrical elastomer sleeve, however, the ratio of radial to axial rigidity is too great, at approximately 5:1 to 10:1.
In the case of a spherical elastomer ball joint, the ratio of cardanic to torsion rigidity is too low, at approximately 3:1 to 5:1.
The aforementioned requirements can therefore not be met simultaneously by either one of the two conventional design principles.                b) Another requirement is that if needed, a mechanical fixed stop that acts in the radial direction can be integrated into the component.        
This requirement, again, cannot be met by either one of the two construction designs mentioned under (a), by itself.